Improvement in framing-squares



C. LAMB. FRAMING-SQUARES.

Patented Aug. 28,1877.

, frwaigqz N. PETERS. PHOTO LTHOGRAPHER UNITED STATES PATENT OEEIoE.

CHRISTOPHER LAMB, OF SAN FRANCISCO, CALIFORNIA.

IMPROVEMENT lN'FRAMlNG-SQUARES.

Specification forming part of Letters Patent No. 194,605, dated August 28, 1877; application filed December 9, 1876.

To all whom it may concern Be it known that I, CHRISTOPHER LAMB, of the city and county of San Francisco and State of California, have invented a new and useful Attachment for a Framing Square, which attachment is fully set forth in the following specification, reference being had to the accompanying drawings.

The object of my invention is to attach a hypotenuse-bar to a framing-square, for the purpose of laying out stairs and getting the lengths and cuts or bevel of rafters.

Figure 1 shows a framing-square, H, with a hypotenuse bar, F, and clasp D attached thereto by a bolt, A, which is more plainly shown at Fig. 2.

Fig. 2 is a section through the center of the bolt A, showing the nut B, the bolt A, the

square H, the clasp D, and bar F.

The bar F is made of wood or metal, and provided with aT-shaped groove, as shown, to allow the head of the boltA to pass through it, so as to hold it to the square H.

The bolt A is provided with a head that will slide through the groove in the bar F, and the bolt'A will project from the bar F, so as to pass through the holes in the ends of the clasp l), as shown at Fig 2. The head of the bolt A has two of its sides made parallel, so as to prevent the bolt A from turning when the nut vB is screwed on or off.

The clasp D may be made of sheet-brass or other metal, cut with a die or otherwise, and bent double, so as to pass over and under the blade of the square H, as shown at Fig. 2, and is provided with holes in both ends, through which the bolt A will pass.

The method of setting the hypotenuse-bar F to any required angle, is as follows: Screw the nut B on one blade of the square tight enough to prevent the clasp D from moving, then slack the nut B on the other blade of the square, and move the bar F to the required angle by moving the clasp D in or out until the bar F comes to the required point, and then set the nut B tight.

I claim as my invention- 1. The combination, with a square, of a grooved bar, F, and clasp D, substantially as shown and for the purpose set forth.

2. The clasp D, constructed substantially as shown, to secure a framing-square to a bar, F, substantially as set forth.

CHRISTOPHER LAMB.

Witnesses:

ROBERT HENRY MowBRAY, FREDERICK GEORGE MACE. 

